Wednesday, September 30, 2015

Chemists have developed novel porous materials called 'covalent organic frameworks,' which provide a basis for the design of polymeric photocatalysts with tunable physical, chemical and electronic properties.

In an effort to help develop a domestic supply of rare earth elements, researchers at Worcester Polytechnic Institute have developed a novel method of chemically separating these materials -- specifically neodymium, dysprosium, and praseodymium -- from the drive units and motors of discarded electric and hybrid cars. The goal is to recycle rare earths that would otherwise be lost in a sustainable and efficient manner.

To get a clearer overall picture of the sources and sinks of nitrogen, scientists have developed a national nitrogen budget for Denmark for the years 1990 to 2010. The budget shows inputs and outputs of nitrogen at national level and the internal flows of nitrogen between the relevant sectors.

Chemical molecules strongly interacting with light generally disintegrate very rapidly. In new research, the main mechanism conducive to this destruction has been determined. This knowledge makes it possible to enhance the photostability of molecules several times over, which is of significance not only for the measurement methods used in laboratory studies, but also for manufacturers of everyday objects, especially those made of colored polymers.

The oceans seem to produce significantly more isoprene, and consequently affect stronger the climate than previously thought. This emerges from a new study of samples of the surface film in the laboratory. The results underline the global significance of the chemical processes at the border between ocean and atmosphere.

Tuesday, September 29, 2015

Scientists have developed a new class of molecular motors that rotate unidirectionally at speeds of up to 1 kHz when exposed to sunlight at room temperature. This unique combination of features opens up novel applications in nano-engineering.

Can portabella mushrooms stop cell phone batteries from degrading over time? Researchers think so. They have created a new type of lithium-ion battery anode using portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce.

Researchers have developed tools that could allow neuroscientists to put aside the fiber optic cable, and use a glowing protein from coral as the light source instead. A variant on the optogenetics technique gives neuroscientists the choice of activating neurons with light or an externally supplied chemical.

Scientists have mapped the strain in graphene, a 2-D sheet of carbon that is strong, flexible and can expand without breaking. Though the material has found its way into several applications, ranging from tennis rackets to smartphone touch screens, several obstacles are holding up further commercialization of graphene. One of these is the presence of defects that impose strain on graphene's lattice structure and adversely affects its electronic and optical properties.

The first atomically thin 2D sheets of organic-inorganic hybrid perovskites have been developed by researchers. These ionic materials exhibit optical properties not found in 2D covalent semiconductors such as graphene, making them promising alternatives to silicon for future electronic devices.

A new study puts us closer to do-it-yourself spray-on solar cell technology—promising third-generation solar cells utilizing a nanocrystal ink deposition that could make traditional expensive silicon-based solar panels a thing of the past.

Friday, September 25, 2015

Scientists have challenged for the design and synthesis of stable, crystalline, porous, covalent organic frameworks. By incorporating electron-donating groups to the phenyl rings of imine linkages, they found that the polarization of imine bonds were softened; this electronic effect reduces the repulsion between layers and strengthens the interlayer interactions to reinforce the stability of the resulting COFs.

Researchers released the final version of a report analyzing policy options for the state of Michigan regarding high-volume hydraulic fracturing, the natural gas and oil extraction process commonly known as fracking.

Researchers have produced the first atomically thin 2-D sheets of organic-inorganic hybrid perovskites. These ionic materials exhibit optical properties not found in 2-D covalent semiconductors such as graphene, making them promising alternatives to silicon for future electronic devices.

With the growth of wind and solar energy and the increasing popularity of electric vehicles, many people in the US may have forgotten about the promised 'hydrogen economy.' But in research labs around the world, progress continues. Now scientists are reporting a new process that could help us move faster toward sustainable hydrogen-based energy.

Chemists have used DNA molecules to developed rapid, inexpensive medical diagnostic tests that take only a few minutes to perform. Their findings may aid efforts to build point-of-care devices for quick medical diagnosis of various diseases ranging from cancer to allergies, autoimmune diseases, sexually transmitted diseases (STDs), and many others. The new technology may also drastically impact global health, due to its low cost and easiness of use, according to the research team. The rapid and easy-to-use diagnostic tests are made of DNA and use one of the simplest force in chemistry, steric effects – a repulsion force that arises when atoms are brought too close together – to detect a wide array of protein markers that are linked to various diseases.

Chemists have invented a nanoscale wrench that allows them to precisely control nanoscale shapes. Their use of 'chirality-assisted synthesis' is a fundamentally new approach to shaping large molecules -- one of the foundational needs for making complex synthetic materials, including new polymers and medicines.

Wednesday, September 23, 2015

A gold catalyst whose behavior can be controlled by the addition of acid or metal ion cofactors has been designed by chemists. They have developed a catalyst with significantly enhanced properties based on a rotaxane, in which a gold catalyst is embedded in the cavity formed by threading a ring shaped molecule around a dumbell shaped axle. On its own , the rotaxane gold catalyst is unreactive but the addition of ions that bind into a pocket in the catalyst framework leads to rapid reactions.

Researchers have now developed a new type of thin film transistor that's significantly faster than its predecessors -- an important step toward speeding up image display on devices like TVs and smartphone screens. The scientists made the transistor from zinc oxynitride, or ZnON, which they then plasma treated with argon gas.

Researchers around the globe are on a quest for materials capable of capturing and storing greenhouse gases. This shared goal led researchers to team up to explore the feasibility of vertically aligned carbon nanotubes to trap and store two greenhouse gases in particular: carbon dioxide and sulfur dioxide.

“CSI: Crime Scene Investigation” is a well-known American TV series where murder cases are solved with the help of precise forensic science. Although these researchers have nothing to do with 'Crime Scene Investigation', the bioinformaticians are experienced readers of trails. They hunt for molecular structures of metabolites, which are chemical compounds that determine the metabolism of organisms.

An ecofriendly catalyst for a certain type of precious metal-mediated chemical reaction has been uncovered by researchers. A new article shows how they tweaked the recipe for an ecofriendly and less expensive version of a metal-based chemical reaction that is essential in the manufacture of several pharmaceuticals.

Biological engineers have devised a new mix-and-match system to genetically engineer viruses that target specific bacteria. The approach could generate new weapons against bacteria for which there are no effective antibiotics.

A new research study examines the market potential and environmental trade-offs of using natural gas in marine fuels. Natural gas is considered by many to be a 21st century energy resource that will enable multiple sectors, including shipping, to transition away from petroleum fuels. But, questions remain about whether the economic and energy potential benefits include co-benefits for the environment.

Researchers have developed a method for synthesizing organic molecules very selectively, by assembling simple molecules and using an enzyme from E. coli (FSA: D-fructose-6-phosphate aldolase), which acts as a biocatalyst. This is a significant step forward since it replicates the formation of carbohydrates in conditions resembling those that presumably initiated life on the Earth (prebiotic conditions) and because it allows relatively large organic molecules to be obtained very selectively and efficiently. Furthermore, it is a process with few steps, that does not use organic solvents and generates no waste, and it has great potential in chemistry, especially for obtaining molecules and active ingredients of interest (drugs, supplements, etc.).

Tuesday, September 22, 2015

Researchers have devised a novel type of graphene oxide-based biosensor that could potentially significantly speed up the process of drug development. The outstanding properties of this carbon allotrope help to improve significantly the biosensing sensitivity, which in future may enable the development of new drugs and vaccines against many dangerous diseases including HIV, hepatitis and cancer.

Unstable crude oil prices and limited oil resources have made the production of petrochemicals from methanol increasingly popular -- above all in China. Scientists have now deciphered the complex chemistry behind the start of this process.

Qin the 1st Emperor of China prepared well for the after-life. Throughout his reign he commissioned and built an eternal army of some 6000 soldiers, charioteers and cavalry. The warriors stood in formation, buried at the foot of his tomb, there to guard the Emperor for eternity.

But all did not go as planned. Shortly after Qin was entombed chaos descended on his newly united China. Qin’s heirs, wishing to defeat him (even after his death) attacked his after-life defences. History tells that the underground barracks that housed the vast army of terracotta warriors were set alight. Fires smouldered for 90 days, structures around the ornate statues collapsed smashing the exquisite army. The broken soldiers and their bronze weaponry lay buried in ash and rubble. The great mausoleum was forgotten. Two millennia passed. Until in 1974, a peasant farmer, whilst digging a well, found fragments of a crushed warrior. And excavations began.

The thousands of individual Qin dynasty soldiers, have been painstakingly pieced together and placed back in formation. They are an awe inspiring sight. But I marvelled just as much when I saw no less incredible bronze weapons that armed the officers. Their swords are still sharp and largely unaffected by the 2200 years that have passed since they were forged. Instead of the green corrosion you’d expect on bronze artefacts the blades actually appear gun metal grey. Why this is the case is something of a mystery.

There are reports of an analysis of the artefacts conducted by the Chinese Research Institute of Nonferrous Metals and Chinese Academy of Geological Sciences (although I am unable to find the primary data). The suggestions is that a 10-15 micron coating containing chromium oxide (at up to 2% chromium) was found. The conclusion; for millennia this thin layer protected objects from the ravages of time and chemistry.

So where did the chromium oxide layer come from? Did the ancient Chinese metallurgists, as suggested by curators of the Terracotta army, really have chrome plating technologies thousands of years before it was developed in the west? Over the intervening time did the chromium shine lose its lustre as it slowly oxidised, resulting in the grey we see today? Is a 10 micron, dilute layer of chromium oxide really enough to impart anti-corrosion properties? Or is there another explanation for the immaculate swords?

This isn’t the first time someone’s asked these questions. Its been discussed on a sword forum where suggestions include forgeries and serendipitous impurities in the alloy. The latter seems to be supported by Prof Frank Walsh, an electrochemist now at Southampton University, when he was interviewed for an ABC documentary back in 2003 where:

Professor Walsh notes that the heat from the fires and the presence of carbon would have provided a reducing environment in which chromium atoms could have migrated to the surface of the weapons. There they’d oxidise and form a protective coating … Metals do diffuse over time, so this ‘natural’ explanation is plausible.

For me this isn’t a totally satisfying explanation. Largely since it appears, from the items on display, that only the blade is free of corrosion. The hilt has clearly corroded. If the slow migration of chromium to the surface of the blade is responsible why didn’t this mechanism occur elsewhere on the swords? But the idea that Qin’s weapon smiths knew how to apply anti-corrosion layers to their creations seems rather fanciful.

Which leaves the above questions unanswered. So chemists, time to reopen discussions. What do you think is going on? Can anyone come up with a way that the ancient Chinese might have deliberately or accidentally protected the weapons? Or what else might have resulted a corrosion free blade, whilst the rest of the weapon is tarnished?

P.S. Any Chinese chemists/metallurgists out there who might be able to track down the analysis of the blades?

Monday, September 21, 2015

A molecular Swiss Army knife has been built by researchers that streamlines the molecular machinery of cyanobacteria, also known as blue-green algae, making biofuels and other green chemical production from these organisms more viable.

Much of the nation's energy policy is premised on the assumption that clean renewable sources like wind and solar will require huge quantities of storage before they can make a significant dent in the greenhouse gas emissions from electricity generation. A new study pokes holes in that conventional wisdom. The analysis finds that the supply of wind and solar power could be increased tenfold without additional storage.

Thursday, September 17, 2015

From almost instantaneous wireless transfer of huge amounts of data and easy detection of explosives, weapons, or harmful gases, to safe 3-D medical imaging and new advances in spectroscopy --- technologies based on terahertz (THz) radiation, the electro-magnetic band with wavelengths from 0.1 to 1 mm, can transform science fiction into reality. However, scientists and engineers still do not have cheap and efficient solutions for mass production of THz-based devices.

Wednesday, September 16, 2015

Researchers show how natural materials like plant cellulose can self-assemble into surfaces with stunning optical properties -- including shiny iridescence and colors that change depending on the humidity.

In the Marvel Comics universe, Professor Xavier and the X-Men are only able to fend off archrival Magneto, the magnetic mutant with the ability to control metals, once they understand the scope of his powers. To better understand the behavior of the microbial world's Magnetos -- magnetically influenced water-dwellers known as magnetotactic bacteria -- three researchers have developed a tool that allows these microscopic species to be studied more easily, especially in their natural environment.

Fossils tell amazing stories and inspire them, too -- just think of this summer's 'Jurassic World' blockbuster. But because some of the processes that preserve fossils are not well understood, there's still more information that they could reveal. Now scientists report a new way to probe fossils to find out how these ancient remains formed in greater detail than before.